The 2009 National Manual on Uniform Traffic Control Devices (MUTCD), issued by the Federal Highway Administration (FHWA), along with the Illinois Supplement to the MUTCD, has been adopted by the Illinois Department of Transportation (IDOT). The 2009 MUTCD and the Illinois Supplement is the official manual for traffic control devices for use on all roads open to public travel in the state. A summary of the significant additions and revisions to the 2009 Illinois supplement is also available.